Ireland has found H5N8 bird flu strain in a wild duck in the south eastern town of Wexford.
The agriculture department confirmed this on Friday.
Several European countries have found cases of H5N8 bird flu in recent weeks.
Ireland ordered that poultry flocks be kept indoors after an outbreak was confirmed in Britain last week.
Further tests are being carried out to determine whether the virus is the same highly pathogenic strain that is currently present in Britain and mainland Europe.
The department said results would be available by mid next week.